"Activity remained at a low level during May. Both Southern and Main Craters released white vapours at weak to moderate rates. However, emissions from Southern Crater occasionally carried ash during the second half of the month and were accompanied by thin blue vapours on the 26th and 28th. Main Crater emissions also contained ash on 4, 5, 10, 16, and 20-23 May. Low rumbling noises from Southern Crater were heard on 2-12 and 19-25 May. Weak ejections of incandescent lava fragments from Southern Crater were seen on the 3rd and 23rd. No significant tilt changes were recorded."

Geological Summary. The 10-km-wide island of Manam, lying 13 km off the northern coast of mainland Papua New Guinea, is one of the country's most active volcanoes. Four large radial valleys extend from the unvegetated summit of the conical basaltic-andesitic stratovolcano to its lower flanks. These valleys channel lava flows and pyroclastic avalanches that have sometimes reached the coast. Five small satellitic centers are located near the island's shoreline on the northern, southern, and western sides. Two summit craters are present; both are active, although most observed eruptions have originated from the southern crater, concentrating eruptive products during much of the past century into the SE valley. Frequent eruptions, typically of mild-to-moderate scale, have been recorded since 1616. Occasional larger eruptions have produced pyroclastic flows and lava flows that reached flat-lying coastal areas and entered the sea, sometimes impacting populated areas.

Information Contacts: H. Patia and P. Lowenstein, RVO.